The present invention relates to an automatic timbre control method and apparatus, and more particularly, to an automatic timbre control method and apparatus which enable automatic timbre control according to a sub-code of the input audio signal, which is assigned a specific code for determining an equalizing mode, by performing a code analysis of the sub-code so as to control a digital equalizer via a microcomputer.
Generally, users determine an audio signal timbre by controlling an equalizer attached to each piece of audio equipment according to the input audio signal. Accordingly, timbre control is performed externally for an audio timbre control apparatus. That is, in the conventional equalizer, external controls are provided in accordance with a plurality of frequency band units, and the user manipulates a control panel of the equalizer so that the desired timbre can be output.
FIG. 1 is a block diagram showing a conventional timbre control apparatus. The apparatus shown in FIG. 1 comprises a compact disc exclusive-use display integration circuit (CD IC) 20, connected to a digital signal input terminal 10, for classifying the audio data and the sub-code from the digital audio signal input via the digital signal input terminal 10, a microcomputer 30, connected to the CD IC 20, for controlling a time checking and CD graphics output determined from the sub-code output from the CD IC 20, a digital equalizer 50, connected to the CD IC 20, for equalizing the audio signal output from the CD IC 20, and a digital-to-analog converter 60, connected to the digital equalizer 50, for converting an equalized digital audio signal output from the digital equalizer 50 into an analog audio signal and for outputting the converted signal via an analog signal output terminal 70.
The operation of the apparatus shown in FIG. 1 will be explained as follows.
A digital audio signal generated from a compact disc is input into the CD IC 20 via the digital signal input terminal 10. The CD IC 20 classifies the input digital audio signal into audio data and a sub-code. The audio data is then supplied to the digital equalizer 50, while the sub-code is supplied to the microcomputer 30. The sub-code is a code that is generally used by the microcomputer 30 as data for time checking or as data used for performing a CD graphics function, e.g., recording information representing words or title of a song.
The digital equalizer 50 divides the audio frequency bands into N bands. A control switch (not shown) is attached to the equalizer 50 so that equalization control can be performed according to the frequency band. In this manner, users adjust timbres by audio frequency band by manipulating the control switch.
The digital equalizer 50, to which the audio data is supplied via the CD IC 20, equalizes the audio data over the frequency bands according to user operation, and outputs the result to the digital-to-analog converter 60.
The digital-to-analog converter 60 converts the digital audio signal equalized by the digital equalizer 50 into an analog audio signal, and outputs the result via the analog signal output terminal 70.
In the conventional timbre control apparatus, a user frequently manipulates the digital equalizer according to the input music pattern so as to determine the timbre. Moreover, a user unfamiliar with the manipulation of a digital equalizer may listen to all music with one setting, or the quality of the music may be reduced due to unskilled equalizing manipulation.